Comparison between direct methods for determination of microbial cell volume: electron microscopy and electronic particle sizing.
AUTOR(ES)
Montesinos, E
RESUMO
Size frequency distributions of different phototrophic and heterotrophic microorganisms were determined by means of scanning and transmission electron microscopy and electronic particle sizing. Statistically significant differences existed among the three techniques used in this study. Cells processed for electron microscopy showed lower mean cellular volumes than those processed for electronic particle sizing, reflecting a shrinkage by factors ranging from 1.1 to 6.2 (mean, 2.3). Processing of cells for scanning electron microscopy caused higher shrinkage than processing for transmission electron microscopy. Shrinkage was dependent neither on the size nor on the cell wall type of the microorganism. When processed for scanning electron microscopy, phototrophic bacteria were strongly shrunken, whereas heterotrophic microorganisms were less affected. A direct relationship existed among phototrophic bacteria between percentage of shrinkage and specific pigment content. This was probably a consequence of the pigment extraction by organic solvents during the dehydration process, previous to the critical point drying, necessary to examine the specimens under the scanning electron microscope.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=242512Documentos Relacionados
- Parameters affecting hospital occupancy and implications for facility sizing.
- Comparison of direct electron microscopy, immune electron microscopy, and rotavirus enzyme-linked immunosorbent assay for detection of gastroenteritis viruses in children.
- Comparison of direct and indirect enzyme immunoassays with direct ultracentrifugation before electron microscopy for detection of rotaviruses.
- Comparison of Rotazyme and direct electron microscopy for detection of rotavirus in human stools.
- Hydrodynamic Focusing and Electronic Cell-Sizing Techniques